Solar due diligence

SolarPro magazine performs industry service with the mother of all PV module reliability feature articles

Although almost every magazine I read incorporates extra bells and whistles in the digital domain—and many have eschewed print altogether—when that bound paper-and-ink corpus shows up in my snail-mailbox, that’s often my wakeup call to start reading a new edition—even if I sometimes do the deed on my trusty laptop or shiny new iPad. The October-November issue of a fave industry trade mag, SolarPro, arrived yesterday, resplendent with a cover feature that I’ve been waiting for on crystalline-silicon PV module reliability and the rise of comparative testing. Senior technical editor David Brearley had approached me about contributing to the piece, but thankfully he left it to the real experts to tell the story about one of the spicier topics of discussion in the solar community. That said, in the interest of full disclosure, I was happy to see David riff on the Curator’s “Pachyderm in the PV Palace” post from earlier this year. Nothing like self-referential curation to massage one’s writerly ego.

The delightfully long-form article can be broken down into two main constituent sections, along with a handful of accompanying sidebars and requisite photography. David starts his piece with an informative table-setting conversation, which talks about the state of the industry and its impact on module quality and performance, followed by an overview of the main safety and design qualification tests, the advent of comparative accelerated testing, the state of quality assurance, and several labeling and sampling issues. Although one could, if one was so inclined, cobble together much of the information he provides from different sources, it’s great to have the disparate strands in one place. Before diving into the second part of the article, he revisits Todd Woody’s much-referenced New York Times article about the supposed rise of defective panels in recent years.

David then lets the experts do the talking, with Q&A-style interviews posing a mix of recurring and specific questions of NREL living legend Sarah Kurtz, Intertek’s testing titan Sunny Rai, mover-and-shaker Jenya Meydbray of PV Evolution Labs, concerned citizen Brian Grenko of Yingli Green, seen-it-all 33-year industry vet Raju Yenamandra of SolarWorld, DuPont Photovoltaic Solutions’ glass half-empty/half-full guy Conrad Burke, consultant-contrarian Jeff Wolfe, and duly diligent PV specialist Hugh Kuhn. Several of those contributing—Kurtz, Rai, Meydbray, and Burke–have been oft-quoted in other media coverage of the topic (Jenya and Connie were cited in the [in]famous NYT piece), so it’s refreshing to also hear from some “new” voices.

To complete the package, Doug Puffer and SolarPro publisher/editor Joe Schwartz assembled the 2013 version of the magazine’s 849-module-strong specifications grid dataset. Combined with David’s feature, the c-Si panel guide brings the total offering to a whopping 34 (!) folio pages.

Here are a few gleanings from the read-worthy comments of the subject matter authorities, admittedly taken out of context of the flow of their respective interviews. But juicy nonetheless.

Grenko: It is evident that certain industry players quoted in these articles have opportunistically aligned themselves to proliferate a coordinated campaign of fearmongering while attempting to create market pull for their own products and services. Our industry is facing a crisis of integrity as much as, if not more than, a crisis of quality. I am confident that most people see right through this. While some may gravitate towards negative headlines like “The Dark Side of Solar,” the reality, as many of us know, is that our industry on the whole is actually flourishing and creating downstream jobs, despite consolidation.

Yenamandra: What scares me is that the sweetness of the low price will one day be completely overshadowed by the bitterness of failures. What if a company supplying a large quantity of modules has wide-scale failures related to the use of unproven materials? If products fail, the media—especially people who are not within the industry—will see that particular solar projects are failing and conclude that solar has failed. The media will paint the industry with a big broad brush. If I am a banker reading those reports, I do not know all of the details. But do I want to fund solar projects? Now I am not so sure. I need more data, more proof. In the short term, I do not see module failures to be a huge problem. They are more of a nuisance, a hassle that will leave a bad taste in the mouth of customers. But I hope and pray that we do not have mass failures in the long term. If we do, that will be a huge disservice to the industry, which took a long time to grow to where it is today.

Wolfe: Creating and implementing a worthwhile international reliability test standard for PV modules is an unnecessary exercise in bureaucracy. PV modules are exposed to an extremely wide set of conditions, from desert heat to arctic chill. Creating a single test regimen that would sufficiently test and qualify a product under all conditions would be an extremely lengthy and ultimately unproductive exercise, potentially providing a false sense of comfort for customers. As with any major long-term purchase, customers should understand what qualities they want and need, and then work with a qualified manufacturer or distributor to provide a suitably qualified product. This is how it works in other construction industries. The solar PV industry does not gain anything by being different.

Kuhn: While building a PV system is not rocket science, the materials science that goes into building a PV module is pretty close to it. Unfortunately, I have yet to see a bankability study that discusses the pros and cons of the backsheet laminate used, the formulation of EVA, the quality of the solder flux used or the testing done to ensure that the resulting end product is reliable and durable. A module firm can have awesome quality assurance and build a product that passes low-bar certification tests every time, but the product reliability and durability over time could be pathetic.

Ready to read the entire feature? The online version can be found here.